Fuel pump arrangement for an oil burner



April 4, 196 o. ECKERLE ETAL 3,312,177

FUEL PUMP ARRANGEMENT FOR AN OIL BURNER Filed April 22, 1965 4sheets-sheeti- April ,1967 o. ECKERLE ETAL 3,312,177

FUEL PUMP ARRANGEMENT FOR AN OIL BURNER Filed April 22, 1965 4Sheets-Sheet 2 /n u'anfors 0/70 ic/r'ek/e f/e/muf lde/b ek/ 76/ MM QApril 4, 1967 o. ECK ERLE ETAL FUEL PUMP ARRANGEMENT FOR AN OIL BURNERFiled April 22, 1965 4 Sheets-Sheet 5 FIG. 3

April 4, 1967 o. ECKERLEI ETAL 3,312,177

FUEL PUMP ARRANGEMENT FOR AN OIL BURNER 1 Filed April 22, 1965 4Sheets-Sheet 4 FIG. 4

United States Patent Ofifice 3,312,177 Patented Apr. 4, 1967 3,312,177FUEL PUMP ARRANGEMENT FOR AN OIL BURNER Otto Eckerle, 3 an! Bergwald,Malsch, Kreis Karlsruhe, Germany, and Helmut Weinzierl, Rastatt,Germany; said Weinzierl assignor to said Eckerle Filed Apr. 22, 1965,Ser. No. 449,940 Claims priority, ap lication Germany, Feb. 5, 1965, E28.634 12 Claims. (Cl. 103-126) This invention relates to the fuelsupply of oil burning furnaces, and particularly to a fuel pumparrangement for an oil burner.

The object of the invention is the provision of a fuel pump capable ofhigh intake suction.

A corresponding object is the provision of a pump arrangement in whichthe intake conduits and associated elements are sealed against inwardpenetration of ambient air, and in which air or other gases entering thepump with the liquid fuel are promptly eliminated.

A further object is the provision of a pump arrangement in whichflashback from the associated oil burner to the fuel system is reliablyprevented when the pump stops supplying fuel to the burner.

In its more specific aspects, the invention is concerned with a fuelpump which is a gear pump having one internally toothed rotor and anexternally toothed rotor of smaller pitch circle in meshing engagement,and it is an additional object of the invention to provide the closestpossible clearances between the rotors and the associated stationarypump elements.

Yet another object is a pump arrangement of the type described whichincludes a simple and rugged valve simultaneously capable of maintaininga desired maximum pressure in the fuel delivered to the burner, ventingair from the fuel, and automatically disconnecting the burner from thefuel system as soon as the fuel stream stops.

With these and other objects in view, as will hereinafter becomeapparent, the pump arrangement of the invention contemplates the use ofa pump casing defining a cavity which is closed by a cover membersecured to the casing, and which communicates with a suction conduit anda discharge conduit. Rotor means are movably arranged in the pump cavityfor drawing a fluid into the cavity through the suction conduit, and fordischarging the fluid under pressure through the discharge conduit. Acap member encloses an upwardly extending filter compartment about thepump cover. The suction conduit has an orifice in the topmost portion ofthe filter compartment. An intake is provided for admitting fluid to thefilter compartment.

Other features and many of the attendant advantages of this inventionwill become readily apparent from consideration of the followingdetailed description of preferred embodiments relating to the annexeddrawings in which:

FIG. 1 shows an oil burner pump of the invention in side-elevationalsection on the line II in FIG. 2;

FIG. 2 shows the pump of FIG. 1 in front elevational section on the lineIIII in FIG. 1;

FIG. 3 shows the same pump in section on the line IIIIII in FIG. 1;

FIG. 4 is a sectional plan view of the pump taken on the line IV-IV inFIG. 3; and

FIG. 5 shows a detail of the pump in section on the line VV in FIG. 2.

Referring now to the drawing in detail, and initially to FIG. 1, thereis seen a gear pump whose drive shaft 1 is journaled in the pump casingand carries an internally toothed cup-shaped rotor 2. The teeth of therotor 2 mesh with the external teeth of a rotor 3 of smaller pitchdiameter which is mounted on a shaft 4 journaled in a pump cover 5, andwhose axis is offset from that of the shaft 1 as is best seen in FIG. 3.A sickle-shaped stationary member 6 fills the gap between those teeth ofthe rotors 2, 3 which are not in meshing engagement. The member 6 issecured to the cover 5 by two pins 7, 8. The circular pump cover 5 isattached to the casing 10 by a locating pin 11 and by four machinescrews 9 whose heads abut against the cover (see FIG. 4), and whoseshanks pass through corresponding smooth bores of the cover withsufficient clearance to permit some pivotal movement of the cover aboutthe pin 11 when the screws 9 are loosened, thereby ensuring alignment ofthe member 6 with the teeth of the rotor 2.

If so desired, the pins 6, 7 may be replaced by a single pin fastened tothe cover 5 and engaging a slot in the center of the member 6 in amanner not further illustrated. Such an arrangement provides alignmentbetween the member 6 and the teeth of both rotors 2 and 3 during pivotaladjustment of the position of the pump cover 5.

Reverting to FIG. 1, there is seen a screw cap 13 which is attached tothe casing 10 by an internally flanged, threaded ring 15 and encloses afilter compartment 14 in which an oil filter 12, indicated by brokenlines, may be mounted on the cap 13. The filter, which is ring-shaped,envelops the pump cover 5. The cover engages an annular rib of thecasing 10 and radially overhangs the rib so that an annular groove isformed in which the threaded ring 15 is sealingly fastened under thepressure of the screws 9 by means of integral projections 16 on theflange of the ring. As best seen in FIG. 4, an integral lug 17 on theflange of the ring 15 extends from the filter compartment 14 into anaxial suction duct 18 in the casing 10, and thereby secures the ring 15against rotation. The cap 13 is preferably made of transparent materialto permit observation of the oil before it enters the pressure space ofthe pump.

A sheet metal partition 19 attached to the cover 5 separates anelongated upright channel 20 from the filter compartment 14. The orificeat the open top end 21 of the channel 20 communicates with the topmostportion of the filter compartment through the filter 12 when the same isinstalled. The bottom of the channel is longitudinally closed. As isapparent from FIG. 2, the aforementioned suction duct 18 communicateswith two internally threaded intake openings 22, 23 is the casing 10either of which may be connected to an oil storage tank for convenienceof installation whereas the other one is normally plugged as shown at23.

Oil admitted to the filter compartment through one of the intakeopenings 22, 23 and the suction duct 18 passes through the channel 20and an aperture 24 in the cover 5 (FIG. 1), which transverselycommunicates with the channel 20 at the closed end thereof, into thepump chamber in which the rotors 2, 3 operate, and is discharged througha discharge duct 25 which tangentially enters anannular space 26 about avalve 27 which will presently be described in more detail. The oil isdischarged under pressure from the casing 10 through a discharge orifice28 (FIG. 2) to the oil burner nozzle.

The discharge duct 25 also communicates through a connecting bore 29with a chamber 30 in the casing 10 through which the shaft 1 passes. Thechamber 30 is sealingly separated from the remainder of the cavity inthe casing 10 by the radial imperforate rear wall of the rotor 2,whereby the rotor is urged axially toward the pump cover 5 by thepressure of the pumped fluid for sealing engagement with the cover andwith the rotor 3. The chamber 30 also communicates through a bore 37with a normally plugged auxiliary outlet 38 in the casing 3 from whichpressure fluid for operating hydraulic furnace controls may be drawn ifso desired.

When the pressure of the pumped oil exceeds a predetermined pressure,oil is returned by the afore-mentioned valve 27 to the non-illustratedstorage tank through a pressure-relief bore 31 and a return lineconnector 32 shown in FIG. 2 when the tank is located to permit returnflow of the oil by gravity. If the pump is connected to a tank locatedat a higher level, the connector 32 is preferably plugged. A branch duct33 communicates with the bore 31 and extends from its junction with thebore 31 in two opposite directions as best seen in FIG. 4. One terminalportion 36 of the duct 33 is longitudinally closed, the other terminalportion has a flaring orifice communicating with the filter compartment14, and is normally closed by a conforming plug 34 of oil resistant,resilient plastic. The plug 34 is prevented from movement inward of theduct 33 by the conforming engagement of its flaring head with theorifice of the duct, and is retained in the duct by the flange of thethreaded ring 15. As best seen in FIG. 3, a notch 35 in the flange islarge enough to permit flow of oil between the duct 33 and the filtercompartment 14 in the absence of the plug 34, but its edges extend overthe plug to secure it in its position. If gravity return of excess oilis not available, the screw 'cap 13 is removed from the pump, and theplug 34 is driven forcibly into the blind terminal duct portion 36,thereby connecting the bore 31 with the filter compartment 14 for returnof excess oil under pressure to the suction side of the pump.

The valve arrangement which maintains a desired maximum pressure in thefuel delivered to the burner, and connects the fuel supply to the burneronly when the pump reaches a predetermined speed, and which disconnectsthe burner from the fuel supply when the pump speed drops below thepredetermined value is best seen in FIG. 2.

A horizontal bore 39 in the pump casing 10 has an axially centralportion in which a main piston 40 is slidably received. The piston 40 ofcircular cross section encloses a generally cylindrical coaxial space inwhich an auxiliary piston 41 is axially movable. A helical compressionspring 42 biases the piston 40 toward the left, as viewed in FIG. 2, andthis direction will hereinafter be referred to as forward.

The axially terminal enlarged portions 43, 44 of the bore 39 arepartially threaded. A plug 46 is threadedly received in the forwardterminal portion 44 and has an axial passage 45 with an enlarged inneror rear orifice 47 in which an annular gasket 48 is arranged. Thethreaded discharge orifice 28 in the plug 46 is normally connected tothe oil burner.

The rear terminal portion 43 of the bore 39 threadedly receives a pipenipple 49 whose bore is movably sealed by the head 50 of a screw 51. Thescrew is secured against outward displacement from the nipple 49 by anintegral shoulder of the latter and carries an internally threaded ring52. The aforementioned spring 42 is interposed between the ring 52 andthe main piston 40 so that the tension of the spring can be adjusted bythreaded movement of the ring 52 on the screw 51.

A radial lug 53 on the ring 52 slidably engages an axial slot 54 in asleeve 55 which is fixedly fastened by a press fit in the bore of thenipple 49. The outwardly accessible end face of the screw head 50 has ahexagonal recess 56 for insertion of a conforming key by means of whichthe tension of the spring 42 may be adjusted. The screw 51, the mainpiston 40, and structure associated with the latter axially bound a rearvalve compartment 57 in the bore 39. A corresponding front valvecompartment at the piston 40 near the plug 46 has an annular portionabout the conical front end of the piston 40, and is enlarged when thepiston moves rearward from the illustrated position in which the frontface of the piston 40 sealingly engages a gasket 47.

A rearwardly open axial bore 58 in the auxiliary piston 41 communicatesdirectly with a relatively wide first (or rear) radial bore 59 in thepiston 41, the two outer ends of the bore 59 being located in an annulargroove 60 in the outer face of the piston 41. The axial bore 58 alsocommunicates with a second (or forward) radial bore 62 in the piston 41through a metering orifice 61 of reduced flow section. The outer ends ofthe bore 62 are located in a second annular groove 63 in the generallycylindrical outer face of the piston 41. p I,

A helical compression spring 64, much weaker than the spring 42, urgesthe auxiliary piston forward toward an abutment 76 on the main piston40. The tension of the spring 64 may be adjusted by means of a screw 65which is threadedly mounted in a coaxial flanged nipple 67 attached tothe piston 40 by a short sleeve 66 of spring metal. The screw 65 and thenipple 67 close the rear end of the piston 40.

Two radial bores 68 in the main piston 40 communicate with the groove 60in all operative positions of the pistons 40, 41-. The outer orifices ofthe bores 68 are located in an annular groove 69 of the main pistonwhich is sealed by the wall of the bore 39 in the position of the valveillustrated in FIG. 2. An annular sealing edge 70 at the rear end of thebore 58 cooperates with a corresponding edge on the nipple 67 to sealradial bores 71 in the main piston 40' when the auxiliary piston 41moves rearward from the illustrated position relative to the main piston40.

As is better seen in FIG. 5, two narrow axially elongated slots 72, 73in diametrically opposite portions of the outer face of the main piston40 provides a throttling passage. Two bores 74, 74 in the main piston 40connect the space 26 with the interior of the main piston 40 ahead ofthe auxiliary piston 41. Two bores 75, 75' in the main piston 40 connectthe annular groove 63 in the auxiliary piston 41 to the frontcompartment ahead of the main piston 40. As seen in FIG. 5, the bores74, 74' are offset from the bores 75, 75.

The valve arrangement operates as follows:

When the pump is started, oil is delivered through the discharge duct 25into the annular space 26. The oil passes through the slots 72, 73 andthe bores 75, 75' into the bores of the auxiliary piston, and isdischarged from the radial bores 71 of the main piston 40 into the rearcompartment 57 and to the pressure relief duct 31. The configuration ofthe piston 40 is such that the flowing oil does not exert significantaxial pressure on the main piston 40 at this stage.

The metering orifice 61, however, produces a throttling effect whichresults in a pressure differential between the oil in front of thepiston 41 and the oil in the rear of the auxiliary piston. When the oilflow reaches a certain rate during acceleration of the pump, thepressure differential becomes sufficient to overcome the restraint ofthe spring 64, and the auxiliary piston is moved rearwardly away fromthe abutment 76. Engagement of the edge 70 with the nipple 67 seals thebores 71, and the pressures behind the metering orifice 61 and in thefront valve compartment is rapidly increased.

The main piston 40 is thereby moved rearward, and a conduit connectingthe front valve compartment and the discharge orifice 28 through thepassage 45 is opened.

The annular groove 69 in the main piston 40 simul-- taneously rides overthe shoulder that separates the narrower central portion of the bore 39from the enlarged terminal portion 43, and any pumped oil in excess overthe requirements of the connected burner is returned to the oil tank orto the intake of the pump through the bores 75, 75 in the main piston40, the axial bore 58 and the radial bore 59 of the auxiliary piston 41,the groove 60, the bore 40, the groove 69, and the rear compartment 57.

When the pump drive is deenerg'i zed, and the oil flow drops below arate that can be precisely preset, the pistons 40, 41 are moved forwardby the associated biasing springs, whereby the groove 69 is blocked andthe bores 71 are opened. The flow of oil is interrupted instantaneously,and the oil pressure in the orifice 28 drops abruptly to practicallyzero.

The full amount of the oil delivered by the pump is thus utilized forestablishing a pressure differential across a throttling passage, andthe auxiliary piston 41 responds to the differential. The setting of thetension in the spring 64 is entirely independent of the spring settingfor the main piston 40 by the screw 51. The screw 51 may be turned, andthe tension of the spring 42 may thereby be altered without affectingthe force'of the spring 64. The auxiliary piston starts its movementshortly before the pump reaches its design speed corresponding to fullcapacity discharge of oil. The valve thus opens shortly before the pumpoutput reaches its desired rate, and it closes as soon as this rate isno longer fully maintained.

The metering orifice 61 in the auxiliary piston 41 assists the closingmovement of the piston 41, and helps to hold the piston 41 in the closedposition. In the absence of such a throttling device, a condition ofequilibrium between the spring pressure and the fluid pressure acting onthe piston 41 may be established in which the piston may no longer moveinto the closing position under precisely predictable conditions, andmay be lifted from its seat from time to time. The pressure drop causedin the metering orifice 61 provides an additional force acting on thepiston 41 in the direction of closing movement.

The suction conduits of the oil burner pump of the invention arereliably sealed against the entry of air, and the pump thus has a highsuction effect. The formation of air pockets in the filter compartmentand other portions of the suction area is prevented by the provision ofthe partition 19 whose orifice 21 is located near the highest point ofthe filter compartment 14. The compartment is tightly sealed by thethreaded cap 13 which is not subject to leakage due to deformation whichcould occur under the pressure of fastening screws.

Axial clearance between the rotors of the pump and the cooperatingstationary pump elements is held to a minimum by the provision of thechamber 30 filed with oil under pressure which urges the rotors againstthe pump cover. Radial clearance between the rotors and the stationarymember 6 can be held extremely small because of the pivotal mounting ofthe cover 5 on the locating pin 11.

As soon as the flow of oil to the burner nozzle subsides, the conduitleading from the pump to the nozzle is closed rapidly, and the danger offlashback, always present at this stage of burner operation, isvirtually eliminated.

It should be understood, of course, that the foregoing disclosurerelates to only a preferred embodiment of the invention, and that it isintended to cover all changes and modifications of the examples of theinvention herein chosen for the purpose of the disclosure which do notconstitute departures from the spirit and scope of the invention setforth in the appended claims.

What is claimed is: a

1. A pump arrangement for an oil burner comprising, in combination:

(a) a pump casing defining a cavity therein;

(b) a cover member secured to said casing and substantially closing saidcavity;

(c) a suction conduit and a discharge conduit communicating with saidcavity;

(d) rotor means movable in said cavity for drawing a fluid into saidcavity through said suction conduit and for discharging said fluid underpressure through said discharge conduit;

(e) a cap member enclosing an upwardly extending filter compartmentabout said cover, said suction conduit having an orifice in the topmostportion of said compartment;

(f) intake means for admitting fluid to said filter compartment; and

(g) a threaded ring, a portion of said ring being interposed betweensaid casing and said cover member for sealingly securing said ring tosaid cover member and to said casing, said cap member threadedlyengaging said ring.

2. An arrangement as set forth in claim 1, further comprising connectormeans on said casing and communicating with said discharge conduit forsupplying operating fluid under pressure to hydraulic control means ofan associated oil burner.

3. An arrangement as set forth in claim 1, wherein said intake meansinclude a duct formed in said casing, said ring being threaded about anaxis and said duct being spaced from said axis, a portion of said ringextending into said duct for securing said ring against rotation aboutsaid axis.

4. A pump arrangement for an oil burner comprising, in combination:

(a) a pump casing defining a cavity therein;

(b) a cover member secured to said casing and substantially closing saidcavity;

(0) a suction conduit and a discharge conduit communicating with saidcavity;

(d) rotor means movable in said cavity for drawing a fluid into saidcavity through said suction conduit and for discharging said fluid underpressure through said discharge conduit;

(e) a cap member enclosing an upwardly extending filter compartmentabout said cover member, said suction conduit having an orifice in thetopmost portion of said compartment;

(f) intake means for admitting fluid partrnent; and

(g) a partition member on said cover member, said partition memberseparating a vertically elongated channel from said filter compartment,said channel constituting a portion of said suction conduit and havingan open upper end constituting said orifice of said suction conduit, anda longitudinally closed lower end, said cover member being formed withan aperture communicating with said cavity and with said lower end.

5. A pump arrangement for an oil burner comprising,

in combination:

(a) a pump casing defining a cavity therein;

(b) a cover member secured to said casing and substantially closing saidcavity;

to said filter com- (c) a suction conduit and a discharge conduitcommunicating with said cavity;

(d) rotor means movable in said cavity for drawing a fluid into saidcavity through said suction conduit and for discharging said fluid underpressure through said discharge conduit;

(e) a cap member enclosing an upwardly extending filter compartmentabout said cover member, said suction conduit having .an orifice in thetopmost portion of said compartment; and

(f) intake means for admitting fluid to said filter compartment,

(1) said rotor means including two meshingly engaged gear membersrotatable about respective axes extending in a common direction, one ofsaid gear members being axially abuttable against said cover member andsealingly separating a chamber remote from said cover member in an axialdirection from the remainder of said cavity, said chamber communicatingwith said discharge conduit,

(2) whereby said one gear member is urged into axial abutment againstsaid cover member by fluid under pressure entering said chamber fromsaid discharge conduit.

6. A pump afnangement for an oil burner comprising,

in combination:

(a) a pump casing defining a cavity therein;

(b) a cover member secured to said casing and substantially closing saidcavity;

() a suction conduit and a discharge conduit communicating with saidcavity;

(d) rotor means movable in said cavity for drawing a fluid into saidcavity through said suction conduit and for discharging said fluid underpressure through said discharge conduit, said rotor means including (1)an internally geared rotor member,

(2) an externally geared rotor member having a smaller pitch diameterthan said internally geared member and meshingly engaging the same forjoint rotation about respective, substantially parallel, spaced axes ofrotation, whereby said rotor members define therebetween a substantiallysickle-shaped space, and

(3) a fill-er member interposed between said rotor members in saidspace, said casing and said cover member constituting wall elements ofsaid cavity, said filler member being mounted on one of said wallelements;

(e) pivot means securing said one wall element to the other wall elementfor pivoting movement about a pivoting axis spaced from said axes ofrotation;

(f) fastening means for fixedly connecting said wall elements in aselected pivotal position;

(g) a cap member enclosing an upwardly extending filter compartmentabout said cover member, said suction conduit having an orifice in thetopmost portion of said compartment; and

(h) intake means for admitting fluid to said filter com .partment.

7. An arrangement as set forth in claim 6, further comprising a pin onsaid one wall element, said filler member being formed with a slottherein, said pin extending in the direction of said pivoting axis andengaging said slot.

8. An arrangement as set forth in claim 1, further comprising pressurerelief valve means communicating with said discharge conduit, a ductconnecting said pressure relief valve means to said filter compartment,and a plug of resilient material in said duct.

9. An arrangement as set forth in claim 8, said duct having a flaringorifice communicating with said filter compartment, said plug having ahead conformingly received in said orifice, and said ring engaging aportion of said head for preventing movement of said plug outward ofsaid orifice into said filter compartment.

10. A pump arrangement for an oil burner comprising, in combination:

(a) a pump casing defining a cavity therein;

(b) a suction conduit communicating with said cavity;

(0) a discharge conduit;

(d) valve means interposed between said cavity and said dischargeconduit;

(e) rotor means movable in said cavity for drawing a fluid into saidcavity through said suction conduit and for discharging said fluid underpressure through said valve means; and

(f) a pressure relief conduit, said valve means includ- (1) meansdefining .a bore, said bore having an axis,

(2) a main piston in said bore, said main piston being formed with anaxially extending internal space and separating a forward compartment insaid bore from a rear compartment in the bore, said discharge conduithaving an orifice in said forward compartment, and said main pistonbeing axially slidable in said bore toward and away from a forwardposition in which said piston blocks said orifice, a rear portion ofsaid space normally communicating with said pressure relief conduit,

(3) first yieldably resilient means biasing said piston toward saidposition thereof,

(4) an auxiliary piston axially slidable in said space toward and awayfrom a rear position in which said auxiliary piston blocks communicationbetween said rear portion of said space and said pressure reliefconduit,

(5) second yieldably resilient means biasing said auxiliary piston awayfrom said rear position thereof, said main piston being formed with abore connecting said cavity with a portion of said space forward of saidauxiliary piston,

(6) said pistons jointly defining a throttling conduit permanentlyconnecting said forward and rear portions of said space, and

(7) said auxiliary piston having-a face transverse of said axis in saidforward portion of said space.

11. A pump arrangement as set forth in claim 10, further comprising acap member enclosing an upwardly extending filter compartment, saidsuction conduit having an orifice in the topmost portion of saidcompartment; and intake means for admitting fluid to said filtercompartment.

12. A pump arrangement as set forth in claim 11, further comprising acover member secured to said casing and substantially closing saidcavity, said filter compart ment extending about said cover member.

References Cited by the Examiner UNITED STATES PATENTS 1,497,050 6/1924Wardwell 103-126 1,776,921 9/1930 Moessinger 230152 2,544,990 3/1951Harrington et a1. 103220 2,684,637 7/1954- Erikson 103-426 2,751,8476/1956 Erikson 103-220 2,775,206 12/1956 Connelly 1 03126 2,813,48811/1957 Deska 103-126 2,880,674 4/1959 Klessig 103220 2,918,013 12/1959Eames 103--126 2,931,314 4/1960 Erikson et a1. 103-126 DONLEY J.STOCKING, Primary Examiner.

WILBUR I. GOODLIN, Examiner.

1. A PUMP ARRANGEMENT FOR AN OIL BURNER COMPRISING, IN COMBINATION: (A)A PUMP CASING DEFINING A CAVITY THEREIN; (B) A COVER MEMBER SECURED TOSAID CASING AND SUBSTANTIALLY CLOSING SAID CAVITY; (C) A SUCTION CONDUITAND A DISCHARGE CONDUIT COMMUNICATING WITH SAID CAVITY; (D) ROTOR MEANSMOVABLE IN SAID CAVITY FOR DRAWING A FLUID INTO SAID CAVITY THROUGH SAIDSUCTION CONDUIT AND FOR DISCHARGING SAID FLUID UNDER PRESSURE THROUGHSAID DISCHARGE CONDUIT; (E) A CAP MEMBER ENCLOSING AN UPWARDLY EXTENDINGFILTER COMPARTMENT ABOUT SAID COVER, SAID SUCTION CONDUIT HAVING ANORIFICE IN THE TOPMOST PORTION OF SAID COMPARTMENT; (F) INTAKE MEANS FORADMITTING FLUID TO SAID FILTER COMPARTMENT; AND